The present invention relates to a bone density meter that uses light to measure bone density.
Methods for measuring the bone density of a measurement subject, such as a person, using light are known in the prior art. Japanese Laid-Open Patent Publication No. 2008-155011 describes one example of a bone density meter. The bone density meter includes a light emission unit, a light reception unit, a variation tendency calculation means, and a density calculation means. The light emission unit emits light into the measurement subject as it varies the light intensity. The light reception unit receives the reflection of the emitted light from the measurement subject. The variation tendency calculation means calculates a variation tendency from the intensity of the reflection light. The density calculation means calculates the bone density of the measurement subject from the variation tendency. In this manner, the bone density meter of the prior art varies the intensity of the light emitted from the light emission unit to evaluate and measure the bone density from the variation in the intensity of the reflection light.
In the bone density meter of the prior art, when measuring the bone density, for example, at a portion at which the subcutis is thick, light may not reach the bone due to factors such as insufficient output of the light emission unit. In such a case, accurate detection of the bone density is difficult.